Glow-discharge tube



W. SRX

GLOW-DISCHARGE TUBE 2 Sheets-$heet l United States Patent" O "iceGLOW-DISCHARGE TUBE Willem Six, Eindhoven, Netherlands, assignor toHartford National Bank and Trust Company, Hartford, Conn., as trustee aline of a first group is to be connected to a. line of a second groupand in which the electrodes associated with the lines of one group areformed by straight rods, ar-

ranged at regular intervals on a cylindrical surface, the electrodesassociated with the lines of the other group being formed by identical,coaxial rings, which are coaxial to the said cylindrical surface.

Such tubes are known, but the ignition voltages of the various dischargepaths formed at the crossings of the electrode groups may be different,since the intervals between the electrodes increase or decrease from oneend of a group to the other. Such an arrangement is rather complicated,particularly with regard to the required screening between the dischargepaths.

It is also known to provide auxiliary anodes in simple glow-dischargetubes for switching purposes, the ignition pulses being supplied tothese auxiliary anodes.

The present invention has for its object to provide multipleglow-discharge tubes comprising auxiliary anodes for switching purposes,in whichthe discharges do not adversely aifect the switching elementsconnected to the auxiliary anodes.

According to the invention, a multiple glow-discharge tube for switchingpurposes, in which one group of electrodes is formed by a number ofrods, arranged at regu lar intervals on a cylindrical surface and theother group of electrodes is formed by a number of cylindrical rings ofequal diameters and coaxial to the said cylindrical surface, thedischarge paths formed at the crossings of the two electrodes groupsbeing screened from one another by screens of insulating material formedby at discs between the cylindrical rings and by elongated screens inmeridian planes of the cylindrical surface,

comprises auxiliary anodes parallel to the anodes and spaced apart by asmall distance from the cathode at the side of indents inthe cathode.

The main discharge concentrates in the indent in the cathode concerned,so that the auxiliary anode is not located in the direct discharge pathand hence does not assume the potential of this discharge. This wouldhave the disadvantage that the potential of the auxiliary anode withrespect to the other cathodes would exceed the ignition voltage.

In order that the invention may be readily carried into effect, twoexamples will now be described in detail with reference to theaccompanying drawings, in which:

Fig. l is a sectional view at right angles to the axis of a tubeaccording to the invention, in which the screening is formed by micaplates;

Fig. 2 is a sectional view through the axis of the tube of Fig. l andFigs. 3 and 4 show another embodiment, in which the screening is formedby ceramic plates.

Referring now to Figs. l and 2, reference numeral 1 designates the glasscylindrical tube wall. The tube contains a number of at mica discs 2,having a comparative ly large hole in the centre. Between the micaplates provision is made of comparatively low nickel rings 3, whichconstitute the cathodes. The cathodes, of which there are 10, areprovided each with ten indents 4. Elongated mica strips 5, of whichthere are also 10, engage the mica discs 2 with the uses of recesses andare arranged so that they are located on each side of the indents 4 inthe cathodes 3. Opposite the indents 4 are the thick anode rods 6 and oneach side thereof the thin auxiliary anode rods 7. The supply wires forthe ten cathodes, designated by 8, extend through the holes in the rings2 (Fig. 2 shows'only the supply wires 8 of the upper and the lowercathode ring). The tube is iilled with argon at a pressure of 15 mm. Hg.The spacing between the anode rods and the cathode rings is 3 mm., thatbetween the auxiliary anodes 0.3 mm. The ignition voltage of the maindicharge path is about 180 v. without auxiliary current. Duringoperation the auxiliary current is a few tens of ,u amperes. The runningvoltage of the main discharge path is v. with a current of 6 m. amps.The ignition voltage of the auxiliary discharge is to 75 v.

Referring to Figs. 3 and 4, reference numeral 1 designates the glasstube wall. The cathode rods are designated by 9 and the anode rings by10. The wireshaped auxiliary anodes are designated by 11 they havesupply wires 12, to which they are connected by short wire connections13. The ceramic screening plates have ten partitions 15 on the upper andthe lower side, provided with recesses to accommodate the main anodesand the auxiliary anodes. The cathodes have indents 16 at the sides ofthe auxiliary anodes.

Although, owing to the more expensive manufacture, the embodiment shownin Figs. 3 and 4, enters into consideration only for greater series oftubes, this embodiment has the advantage that the electrodes may bestronger than those shown in Figs. l and 2, more particularly, since theanodes are held by the grooves in the ceramic plates.

What I claim is:

l. A multiple glow discharge tube comprising a group of cathode and agroup of anode electrodes between which discharges are produced, one ofsaid groups cornprising a plurality of regularly-spaced rods defining avcylindrical surface, the other of said groups comprising a plurality ofequal-diameter cylindrical rings arranged coaxially with respect to saidcylindrical surface, insulating members for screening the dischargesfrom one another comprising a plurality of ilat discs disposed betweenthe cylindrical rings and a plurality of elongated plates extendingbetween the rods along meridan planes of the cylindrical surface, saidcathode electrodes having indents on the side thereof facing the anodeelectrodes for concentrating the discharge thereat, and a plurality ofauxiliary anodes extending parallel to the anode electrodes and slightlyspaced apart from the cathode electrodes at the side of the indents forinitiating discharges between the cathode and anode electrodes.

2. A multiple glow discharge tube comprising a group of cathode and agroup of anode electrodes between which discharges are produced, saidanode electrodes comprising a plurality of regularly-spaced rodsdefining a cylnidrical surface, said cathode electrodes comprising aplurality of equal-diameter cylindrical rings arranged coaxially withrespect to said cylindrical surface. insulating members for screeningthe discharges from one another comprising a plurality of llat discsdisposed between the cylindrical rings and a plurality of elongatedplates extending between the rods along meridian planes of thecylindrical surface, said cathode electrodes having indents on the sidethereof facing the anode electrodes for concentrating the dischargethereat, and a plurality of auxiliary anode rods extending parallel tothe anode electrodes and slightly spaced apart from the cathodeelectrodes at the side of the indents for initiating discharges betweenthe cathode and anode electrodes.

3. A multiple glow discharge tube comprising a group of cathode and agroup of anode electrodes between which discharges are produced, saidcathode electrodes comprising a plurality of regularly-spaced rodsdening a cylindrical surface, said anode electrodes comprising aplurality of equal-diameter cylindrical rings arranged coaxially withrespect to said cylindrical surface, insulating members for screeningthe discharges from one another comprising a plurality of ilat discsdisposed between the cylindrical rings and a plurality of elongatedplates extending between the rods along meridian planes of thecylindrical surface, said cathode electrodes having indents on the sidethereof facing the anode electrodes 3 4 for loncentrating the dischargthereat, and a plliirality of References Cited in the le of this patentaux' iary circular rods exten ing parallel -to t e anode electrodes andslightly spaced apart from the cathode UNITED STATES PATENTS electrodesat the side of the indents for initiating dis- Number Name Date chargesbetween the cathodeand anode electrodes. 5 2,404,920 Overbeek July 30,1946 2,607,015 Townsend Aug. 12, 1952

